title: Incidence, risk factors and prediction of post-operative acute kidney injury following cardiac surgery for active infective endocarditis: an observational study.
abstract: BACKGROUND
  Cardiac surgery is frequently needed in patients with infective endocarditis (IE). Acute kidney injury (AKI) often complicates IE and is associated with poor outcomes. The purpose of the study was to determine the risk factors for post-operative AKI in patients operated on for IE.
  
  
  METHODS
  A retrospective, non-interventional study of prospectively collected data (2000-2010) included patients with IE and cardiac surgery with cardio-pulmonary bypass. The primary outcome was post-operative AKI, defined as the development of AKI or progression of AKI based on the acute kidney injury network (AKIN) definition. We used ensemble machine learning ("Super Learning") to develop a predictor of AKI based on potential risk factors, and evaluated its performance using V-fold cross validation. We identified clinically important predictors among a set of risk factors using Targeted Maximum Likelihood Estimation.
  
  
  RESULTS
  202 patients were included, of which 120 (59%) experienced a post-operative AKI. 65 (32.2%) patients presented an AKI before surgery while 91 (45%) presented a progression of AKI in the post-operative period. 20 patients (9.9%) required a renal replacement therapy during the post-operative ICU stay and 30 (14.8%) died during their hospital stay. The following variables were found to be significantly associated with renal function impairment, after adjustment for other risk factors: multiple surgery (OR: 4.16, 95% CI: 2.98-5.80, p<0.001), pre-operative anemia (OR: 1.89, 95% CI: 1.34-2.66, p<0.001), transfusion requirement during surgery (OR: 2.38, 95% CI: 1.55-3.63, p<0.001), and the use of vancomycin (OR: 2.63, 95% CI: 2.07-3.34, p<0.001), aminoglycosides (OR: 1.44, 95% CI: 1.13-1.83, p=0.004) or contrast iodine (OR: 1.70, 95% CI: 1.37-2.12, p<0.001). Post-operative but not pre-operative AKI was associated with hospital mortality.
  
  
  CONCLUSIONS
  Post-operative AKI following cardiopulmonary bypass for IE results from additive hits to the kidney. We identified several potentially modifiable risk factors such as treatment with vancomycin or aminoglycosides or pre-operative anemia.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Legrand
authors.forename: Romain
authors.initials: R
authors.lastname: Pirracchio
authors.forename: Anne
authors.initials: A
authors.lastname: Rosa
authors.forename: Maya L
authors.initials: ML
authors.lastname: Petersen
authors.forename: Mark
authors.initials: M
authors.lastname: Van der Laan
authors.forename: Jean-Noël
authors.initials: JN
authors.lastname: Fabiani
authors.forename: Marie-paule
authors.initials: MP
authors.lastname: Fernandez-gerlinger
authors.forename: Isabelle
authors.initials: I
authors.lastname: Podglajen
authors.forename: Denis
authors.initials: D
authors.lastname: Safran
authors.forename: Bernard
authors.initials: B
authors.lastname: Cholley
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Mainardi
mesh_terms: D058186:Acute Kidney Injury / Q000453:epidemiology* / Q000628:therapy; D000328:Adult; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D004696:Endocarditis / Q000601:surgery*; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000628:therapy; D011237:Predictive Value of Tests; D017582:Renal Replacement Therapy; D012189:Retrospective Studies; D012307:Risk Factors